Embodiments of the present invention relate to circuit interrupters and, more specifically, to extinguishing an arc in a circuit interrupter.
An electrical distribution system, such as an electrical grid, may be used to distribute electricity over a region to various facilities or within a facility to various equipment. The distributed electricity may be used to power large-scale and small-scale circuits. Occasionally, in such circuits, an over-current condition such as a short circuit may occur due to degradation of circuit elements, operator error, environmental disturbances, and the like. In order to minimize the damage caused by an over-current condition, a circuit interrupter or circuit breaker may be used. The circuit interrupter generally includes a pair of contacts which, under normal operating conditions, remains closed, allowing current to flow through the circuit. The circuit interrupter is generally configured to detect an over-current condition in the circuit, such as a fault or short circuit. Upon detecting such an over-current condition, the circuit interrupter may trip (open or disconnect the contacts) and the circuit is disconnected.
In some electrical distribution systems, such as DC distribution systems, an electric arc may form between the separated contacts of the circuit interrupter during separation. The electric arc may cause damage to the contacts of the circuit interrupter, shortening their operational life.
Therefore, an arc chute may be included in a circuit interrupter to gradually extinguish the electric arc after separation of the circuit interrupter contacts. Arc chutes generally include structures that stretch an arc by making the arc wrap around arc dividers, such as steel plates. However, such a circuit interrupter employing such an arc extinguishing structure may not be an efficient means of extinguishing electric arcs formed in a DC circuit, as DC current is constant and does not pass a zero point like an AC system does. Thus, a circuit interrupter capable of efficiently extinguishing an electric arc in a DC system is needed.